Alexander Zuckermann, a pioneering bicycle advocate known for his charm and tenacity, died of complications related to a head injury incurred on a midnight bike ride on the Bay Bridge years ago. He was 86.

Mr. Zuckermann was riding on the eastern span of the Bay Bridge with Caltrans officials in 2002, while the bridge was closed for seismic work, when his tire hit an expansion joint and he fell. Even though he was wearing a helmet, Mr. Zuckermann suffered a severe head injury and spent the rest of his life in care facilities.

"He was a tireless advocate for bicycle access in the region," Kimsey said. "He was great to work with because he was so passionate, yet very respectful and knew how to get things done."

Mr. Zuckermann was among the first to persuade BART to allow bicycles aboard its trains and founded the East Bay Bicycle Coalition in 1972. He also lobbied successfully for bike access on the Richmond-San Rafael, Benicia and Carquinez bridges.

Born in 1921 near Berlin, Mr. Zuckermann and his family, who were Jewish, fled Germany in 1938 for New York, where his father ran a leather factory.

When he turned 18, Mr. Zuckermann hitchhiked West and settled in the Bay Area, where he was interested in the cultural scene, said his son, David Zuckermann of El Cerrito.

He received his bachelor's and master's degrees from UC Berkeley and worked for 18 years as a planner for Oakland.

Although he always enjoyed riding his bike to work and for recreation, he fully devoted himself to bicycle advocacy after he retired, David Zuckermann said.

His experience as a bureaucrat and respect for government processes endeared him to officials and activists alike, his family and colleagues said.

"He was like the smiling activist. He was a pleasant gadfly," David Zuckermann said. "When he met with bureaucrats, he bugged the hell out of them, but in a way they liked."

"He was a giant in the bicycle community," said Leah Shahum, the coalition's executive director. "He played a tremendous role in getting a bike path on the Bay Bridge. It was his vision and tenacity and diplomacy that made it happen."

When he wasn't fighting for bike lanes, Mr. Zuckermann was out riding. He rode hundreds of miles every week, and in his 70s completed the Markleeville Death Ride, a 130-mile loop in the Sierra, and the 200-mile Davis Double Century.

"He had a joie de vivre, a sparkle about him," said Phil Morton, former president of the Grizzly Peak Cyclists. "He was certainly an inspiration."

In addition to his son David, Mr. Zuckermann is survived by his son Ron Zuckermann, also of El Cerrito; his former wife, Irma Zuckermann of Berkeley; a brother, Wolfgang Zuckermann of France, and two grandchildren.